The family of a Muslim man whose doctors attempted to withdraw treatment after a heart attack left him with severe brain damage say they feel vindicated after dramatic video evidence emerged in court that suggested he may not be in a vegetative state.

The footage recorded on Wednesday night – and witnessed by a doctor – shows the 55-year-old Muslim man, known as L, responding to requests and commands.

A neurologist at the court of protection in London concluded L was in a minimally conscious state and could not rule out the possibility of further progress and even verbal communication.

Relatives of the man, from Greater Manchester, have been fighting a decision by the Pennine Acute Hospitals Trust that L was beyond recovery after his third heart attack five weeks ago. His doctors had sought an assurance from the court that they did not have to resuscitate him or put him on a ventilator should his condition become life-threatening.

In a dramatic twist on Thursday as the case was about to conclude, L's family produced video evidence to the court and the case was adjourned by Mr Justice Moylan until 1 October.

The family's solicitor, Helen Lewis, an expert in clinical negligence at Manchester law firm Pannone said: "The family feel vindicated in contesting the trust's application, but even more importantly they are relieved that medically L is not in a vegetative state and there is hope of recovery.

"They have asked for their privacy to be respected in the weeks and months ahead as they concentrate on assisting L to make as full a recovery as possible." She said they now await response from the trust as to how their clinicians "reconsider their position in the light of this new and dramatic evidence".

Lewis added: "It is certainly a sobering thought that the trust would have put in place a 'do not resuscitate' order if the family had not challenged their stance through the legal system."

L's family strongly opposed the hospital's stance, telling the court they did not believe he was beyond hope of recovery and that their religion, Islam, required that everything possible should be done to keep L alive.

An independent neurologist, Dr Peter Newman, who had been due to give evidence in support of the hospital, was shown video that he said demonstrated L was no longer in a persistent vegetative state.A trust doctor gave a witness statement in which he accepted that there was "a closing of eyes and grimacing" when L's eyes were cleaned.

On Thursday, Jenni Richards QC, for the family, told Moylan the video was shot during a visit to the hospital on Wednesday night by the family in the company of a hospital doctor, who was not a neurologist.

"That video footage was viewed this morning by Dr Newman as well as by representatives of the family," Richards told the court. "On the basis of what he had seen on the video footage, Dr Newman's view, shared with all the parties, was that Mr L was no longer in a persistent vegetative state."

It was Newman's position that he was now "most likely in a minimally conscious state", said Richards. "He accepts the video footage shows, as the family said, some purposeful responses – some sentient responses – on a different level from those that have previously been observed."

Richards said L could possibly improve further and that Newman did not rule out the possibility eventually of "some verbal communication".

Claire Watson, for the hospital trust, said there had clearly been some change in the diagnosis. She did not yet have "a definitive view from the treating clinicians at the hospital whether or not that will alter their care plan for L", but she thought it was unlikely to do so, given the severity of L's brain damage.

Earlier in the week, before the new evidence emerged, the court heard that the family "wanted to believe" that he was able to respond and the medical opinion was there was no chance of a meaningful recovery. However, the video contradicted this evidence.